Add matrix-appservice-discord bridge

Bridge is setup to work on the matrix side with this, but the discord invite link is not automatically generated.

roles/matrix-synapse/templates/ext/appservice-discord/systemd/matrix-appservice-discord.service.j2

@@ -0,0 +1,29 @@
+[Unit]
+Description=Matrix Appservice Discord server
+After=docker.service
+Requires=docker.service
+Requires=matrix-synapse.service
+After=matrix-synapse.service
+
+[Service]
+Type=simple
+ExecStartPre=-/usr/bin/docker kill matrix-appservice-discord
+ExecStartPre=-/usr/bin/docker rm matrix-appservice-discord
+ExecStart=/usr/bin/docker run --rm --name matrix-appservice-discord \
+			--log-driver=none \
+			-e "UID={{ matrix_user_uid }}" -e "GID={{ matrix_user_gid }}" \
+			--network={{ matrix_docker_network }} \
+			{% if matrix_appservice_discord_container_expose_client_server_api_port %}
+			-p 127.0.0.1:9005:9005 \
+			{% endif %}
+			-v {{ matrix_appservice_discord_base_path }}:/data \
+			{{ matrix_appservice_discord_docker_image }}
+			
+			
+ExecStop=-/usr/bin/docker kill matrix-appservice-discord
+ExecStop=-/usr/bin/docker rm matrix-appservice-discord
+Restart=always
+RestartSec=30
+
+ [Install]
+WantedBy=multi-user.target